He wanted to use the less expensive HC-SR04 ultrasonic rangefinder ... [Clint] was working with the Arduino library, based on the Parallax PING, which uses a single pin for trigger and echo.

He wanted to use the less expensive HC-SR04 ultrasonic rangefinder ... [Clint] was working with the Arduino library, based on the Parallax PING, which uses a single pin for trigger and echo.

Seeing as Arduino is good for controlling motors and sensors, Randy added a PING ultrasonic sensor to the front of the vehicle too. So in addition to driving back and forth, the toy car will now ...